Socket



May 18, 1943. EQR, KULKA I 2,319,693

SOCKET Filed June 8, 1942 II. I

I IN ENTOR.

JJW WWO fi wm/ A TTORNEYS Patented May 18, 1943 UNITED STATES PATENT OFFICE v socKE'r Eugene R. Kulka, Mount Vernon, N. Y.

Application June 8, 1942, Serial No. 446,188 4 Claims. (Cl. 173-328) My invention relates to a new and improved socket for fluorescent lamps and for similar devices.

One of the principal objects of the invention is to provide a socket which will prevent the crossing and jamming of the respective pairs of prongs at the respective ends of the fluorescent lamp or other device, when such pairs are respectively inserted into a pair of sockets.

Another important object of my invention is to provide a socket which has an improved combination of body and insulating cover, so that the body can be made of substantial size, thus making it possible to use resilient contact springs of substantial size, which will securely grip the prongs of the lamp or other device.

Another object of the invention is to provide a simple and compact device which can be manufactured at low cost and which will permit the easy insertion and easy withdrawal of the prongs.

Other objects of the invention will be stated in the annexed description and drawing, which illustrate a preferred embodiment thereof.

Fig. l is a front elevation of the body of the improved socket.

Fig. 2 is a rear elevation of the body of said improved socket, with the insulating cover removed.

Figs. 3 and 4 are respectively sectional views on the lines 3-3 and 4-4 of Fig. 1, showing the cover in position.

Fig. 5 is a bottom plan view ofthe body of the socket.

Fig. 6 is a partial elevation of a fluorescent lamp, illustrating the pair of external and parallel metal prongs at one end of said lamp. The other end of said lamp has another pair of said prongs.

Fig. 7 is a full-sized end elevation of the socket and its bracket, and it shows one endportion of the fluorescent lamp or other device, which has a pair of prongs located in said socket.

Fig. 8 is an elevation of the fiber cover which is an element of the device Fig. 9 is a sectional view on the line 9-9 of Fig. 2.

The socket comprises a rigid shell-body l which is made of any suitable rigid insulating material, which is molded into final shape. Said shellbody has a front wall 2. As shown in Fig. 3, said front wall 2 has a rear surface 2a.

For convenience, the device will be described with reference to the position which is shown in the drawing, although said device can be used in any position.

The shell-body I is provided with lateral end portions 3. The end-portions 3 are identical. Each end-portion 3 has a transverse front-recess 5 and a transverse rear-recess 6. Said recesses ,.communicate with each other, so as to form a bore whose portion 5 is of greater diameter than the portion 4. The longitudinal axis of each recess 5 is coincident with the longitudinal axis of the respective recess l. Each transverse frontrecess 5 preferably has an untapped or smooth inner wall, and each transverse rear-recess 4 is tapped.

The shell-body I is fixed to the vertical metal arm 8 of a bracket B, by means of transverse clamping screws whose shanks 6 are threaded into the internally threaded walls of the rear recesses 4. Said screws have clamping heads 1. Thebracket B has a horizontal metal arm 9, in addition to its vertical metal arm 8 As shown in Fig 2, the rear of the shell-body I has transverse vertical planar walls 20, which are located intermediate the respective pairs of transverse recesses 4 and 5. Each vertical wall 20 is integral with a transverse boss II], which is provided with a recess ll. Each recess ll is closed at the front end thereof, as shown in Fig. 3. A cover C, which is made of insulating fiber or the like, is fixed to the shell-body i by means of drive screws or drive rivets which have shanks l2 and clamping heads M. The inner wall of each recess ll is roughened or provided with ribs, in order to hold the shanks l2 of said drive screws or drive rivets. The shanks l2 of said drive screws or drive rivets pass through holes l5a of the insulating cover C. The cover C is therefore located wholly inwardly of the shellbody i, and the width of the cover C is less than the width of the shell-body I. As shown in Fig. 3, the end-portions 3 extend rearwardly of said cover C.

The top and bottom walls of the shell-body are integral with a vertical rib which has superposed rib-portions, which have different respective depths or transverse dimensions. At its top, said rib comprises-a forwardly extending post or projection I'I whose tip is in the same plane as the planar vertical front wall 2 of the shell-body I. Below said post or projection ll, said rib has a depending rib-portion l6 whose depth is less than the depth of the bottomv wall Ba. of said shell-body I. At and below the bottom of said rib-portion I 6, said rib has a rib-portion 22. The front vertical planar wall of said rib-portion 22 is in the same vertical plane as the front wall 2 of the shell-body. Said rib-portion 22 has 2 v a wedge-shaped top, whose top transverse straight line is indicated in Fig. .4 by the reference numeral 23. The inner end 01' the recess I5 01' cover abuts the convex bottom-wall I30 of said rib-portion 22.

The recess l separates the top portion of the cover into two wings. Each top wing of the cover C is located laterally at a respective side of said rib, at and above the bottom-wall I60 of the rib-portion 22. Said cover C completely closes the opening at the rear of the shell-body I. The vertical walls |5b of said cover C abut or are close to the respective vertical walls of the shell-body, and the top and bottom walls of the cover C abut or are close to the inner surfaces of the top and bottom walls of the shellbody I, at the rear opening of said shell-body I.

The shell-body I is provided with two identical metal contacts 2|, which are made of any resilient metal or alloy. Each said resilient metal contact 2| comprises respective end loops 2|a and 2|b and an intermediate re-entrant loop 2|c. A portion of the bottom loop 2|b of each said metal contact 2| abuts a part of the rib-portion l8, which' is integral with the bottom wall Ba 2 of the shell-body. A part of each top loop 2|a abuts a portion of the inner surface of the top wall of the shell-body. The tip of each top loop 2|a is spaced at all times from the respective vertical wall 20. A part of each bottom loop 2|b abuts a part of the inner surface of the bottom wall Ba of the shell-body. The tip of each bottom loop 2|b abuts the respective vertical wall 20. The resilient metal contact springs 2| are sprung into position, so that said metal contact springs 2| are held frictionally and removably in position. The top loops 2la are free to move away from each other, while the bottom loops 2|b remain anchored in their respective positions.

Fig. 2 shows the normal positions of the spring contacts 2|, to which they are biased by their resilience. As shown in Figs. 1 and 2, portions of the top loops 2|a abut respective transverse edges of the rib-portion 22.

The upper part of the shell body is provided with a recess at each side of the post l1 and of the rib-portion 22. Each said recess has walls and 3|. The drawing is substantially to scale and reference is made thereto for further details.

The bottom wall Ba of the shell-body I has recesses 36 through which the respective insulated wires 31 are passed. The bare tip of each wire 3| is soldered or otherwise conductively fixed to a respective bottom loop 2|b.

The lamp L is provided at each end thereof with a pair of external and parallel metal contact prongs 34 and 35.

The depth of the recesses of th upper part of the shell-body is equal to the depth of the ribportion-IG, which is integral with the top-wall of the shell-body.

When two identical sockets of this type are fixed to the vertical metal arms 8 of a bracket B, said sockets are aligned so that their central points are on a straight line which is perpendicular to the vertical arms 8. This straight line is the longitudinal axis of the fixture.

When the lamp L is properly connected to said sockets, each prong of the lamp L is at a respective side of the rib-portion 22, and in contact with a respective contact spring 2|,"at the respective middle loop 2|c. Each contact spring 2| is then bent away from the normal position which is 2 la is closer to the respective transverse wall 20, than in Fig. 2. Each loop 2|c then clamps the respective prong against the respective adjacent vertical planar face of the rib-portion 22.

In inserting the prongs into the socket, the lamp is held initially with its longitudinal axis parallel to the longitudinal axis of the fixture, and with each pair of prongs 34 and 35 in vertical superposed relation. The bottom prongs at each end of the lamp are then' pushed between respective aligned loops 2|a and the aligned respective transverse edges of the rib-portion 22, to contact with respective aligned walls 3|. The lamp L is then turned around its longitudinal axis, so that the upper prongs are turned over the top 23 of the rib-portion 22. This turning movement is continued, until the two prongs at each end of the lamp are in the same horizontal plane. The prongs 34 and 35 are then parallel to the longitudinal axis of the fixture, and the lamp L has been properly connected to the power circuit by means of the two pairs of wires 31.

In using previous devices of this type, it was possible for a careless person to initially insert the bottom prongs into respective diagonally opposed recesses of the sockets, instead of inserting said bottom prongs into respective aligned recesses. In such case, when the person turned the lamp L around its own axis, said axis of the lamp was inclined to the longitudinal axis of the fixture, instead of being parallel to said longitudinal axis of the fixture. In such case, the turning movement jammed and injured the lamp.

The distance between the apex 23 of the ribportion 22 and the bottom of post I1 is less than the distance between prongs 34 and 35 at each end of the lamp L. The prongs 34 are in respective alignment, and the prongs 35 are also in respective alignment. It is therefore impossible to push the bottom prongs downwardly into the sockets of the fixture, unless the axis of the lamp is parallel to the axis of the fixture, because, if the axis of the lamp is initially inclined to the axis of the fixture, the post 31 of one socket will prevent such downward pushing. The width or diameter of the post I1 is preferably at least equal to the width of the rib-portion 22, although the invention is not limited to this. the diameter of post l1 may exceed or be less than the width of rib-portion 22, as long as the post |1 sufilciently obstructs the fixture above the top of rib-portion 22, so that the lamp L cannot be initially inserted, unless the axis of lamp L is parallel to the longitudinal axis of the fixture.

In prior devices of this type, the body of the fixture was made smaller than the cover, so that the resilient contact and prong-holding springs 2| were made small. Such small springs did not efiiciently clamp the prongs in position, especially if the fixture was an overhead fixture, in which shown in Fig. 2, so that the tip of each top-loop the weight of the lamp urged it downwardly out of the sockets. Vibration would then often loosen or release the lamp from its sockets.

By making the shell-body larger than the cover C, and by means of the improved combination of parts disclosed herein, the springs 2| can be made larger and stronger with thesame overall size of socket and cover, thus producing a superior clamping efi'ect.

All the parts of the shell-body are shaped so that the entire shell-body can be molded integrally, so that the device can be simply and cheaply manufactured.

In order to define the parts of the claims, the

2,319,893 end-portions 3 may be designated as attachment portions. The shell-body I has a rear opening which is located intermediate said attachment portions 3 and said rear opening is closed by the cover C. When the cover C is in its closing position, the inner face of said cover preferably abuts or is close to the respective edges of the contact springs M. The aligned walls 3i, and thefront edges of, the contact springs 2i abut or are close to the rear surface 2a of the front wall 2. The contact springs 2| are thus held against any substantial movement relative to the shell-body I, save that the tips of the loops 2| can move relative to the respective walls 20.

The top and bottom walls of the shell-body are designated as edge walls of said body. The invention is not limited to the shape of the shellbody which is specifically illustrated herein, as said body may beof any shape. In this particular embodiment, the top and bottom edge walls insulating material and which is adapted to connect two parallel adjacent end-prongs of an elecsaid body having a front-wall and an edge-wall, said edge-wall having an edge-wall-recess, said front-wall having a front-wall-recess which is continuous with said edge-wall-recess, said body having a partition rib which divides said frontwall-recess into two sub-recesses, said body having a contact spring at each side of said partition rib, said springs being separated from each other, each said contact spring having a portion which is adjacent to and which is spaced from said partition rib, said body having arvopening at the rear thereof, a cover fixed to said body and located in said body and holding said contact springs against rearward removal out of said body, said body having attaching-portions for attaching said body to a support, said cover being located between said attaching-portions.

4. Aisocket having a body which is made of insulating material, said body having a fronttrical device to the respective terminals of a power circuit, said body having a front-wall and an edge-wall, said edge-wall having an edgewall-recess, said front-wall having a front-walli recess which is continuous with said edge-wallrecess, said body having a partition rib which divides said front-wall-recess into 'two sub-recesses, said body having a contact spring at each side of said partition rib, said contact springs being separated from each other, each said contact spring having a portion which is adjacent to and which is spaced from said partition rib, the respective spaces between said partition rib and said portions being shaped to receive respective prongs which are in contact withv said respective contact springs, said body having a projection which is located in said front-wall-recess and which is spaced from the tip of said partition rib, the

space between said projection and said tip being greater than the width of a single end-prong, said space between said projection and said tip being less than the distance between a pair of said end-prongs.

2. A socket according to claim said contact spring contacts with a respective side of said partition rib, each said contact spring being movable out ofcontact with said partition rib.

. 3. A'socket having a body which is made of insulating material and which is adapted to connect two parallel end-prongs 01 an electric device to the respective sides of a power circuit,

1, in which each.

wall and opposed edge-walls, said socket being adapted to connect two adjacent parallel endprongs of an electric device to the respective terminals of a power circuit, said front-wall having a front-wall-recess, said front-wall-recess being continuous with an edge-wall-recess of one of said edge-walls, the inner surfaces of said edge-walls being integral with a partition rib, one end of said partition rib having a post which extends into said front-wall-recess at the free end thereof, said partition rib having a first ribortion which is spaced from said post and which is integral with said front-wall and which is shaped to provide a bridge which separates said front-wall-recess into two sub-recesses, said bridge having a tip which is spaced from said post, said partition rib having a second rib-portion which is integral with said front wall and whose rear wall is located in front of the rear wall of the first rib-portion, said body having a rear opening whose ends are located laterally inwardly of the respective lateral end-portions of said body, said partition rib extending across said rear opening, a cover made of insulating material, said cover being located in front of the rear wall of said first rib-portion, said cover having a recess which interfits with said first ribportion so that said cover and said partition rib wholly close said rear opening, fastening means located laterally between said lateral end-portionsand fixing said cover to said body, said lateral end-portions or said body extending rear wardly of said cover and being perforated to receive fastening means, said body having contact springs which are separated from each other and which are respectively located on opposite sides of said bridge and between said trout-wall and said cover, portions of said contact springs being exposed in the respective sub-recesses, the distance between said post and said tip being greater than the width of a single end-prong and being less than the distance between said two endprongs.

EUGENE R. KULKA. 

